PROJECT SUMMARY/ABSTRACT A cerebral aneurysm is an abnormal enlargement or pouch that forms from a weakened vessel segment in the brain. Often going unnoticed and untreated, an aneurysm can cause a sudden and catastrophic hemorrhage or stroke. Approximately 15 % of patients die from an aneurysm rupture even before receiving medical attention and 25 % of patients die despite medical treatment. Patients that survive typically suffer from various levels of morbidity. Thus, only one in four patients who suffer a ruptured aneurysm will fully recover. It is estimated that between 3 million and 6 million Americans have cerebral aneurysms, and approximately 30,000 people in the United States suffer hemorrhage each year. While there have been notable recent advances in providing minimally invasive access to aneurysms using advanced micro-catheter systems, there is a paucity of equally high performing embolization materials that can be delivered through these catheters to effectively treat clinically challenging lesions. The purpose of this venture is to provide an innovative biomaterial (PPODA-QT) for the endovascular treatment of aneurysms in order to significantly increase therapeutic effectiveness while minimizing surgical risks. The Phase I proposal developed techniques to test PPODA-QT?s visualization during injection and its mechanical stability and resistance to particulation and downstream migration. Successful testing of PPODA-QT leads to this Phase II proposal - to characterize and optimize PPODA-QT for stability and biocompatibility testing and submission to the FDA for Investigational Device Exemption (IDE) approval. Preliminary studies have shown that PPODA-QT can be formulated and delivered to effectively occlude long-term animal aneurysm models while also promoting a positive bioactive healing response that may permanently stablize an aneurysm. Our goal is to begin validation of these preliminary PPODA-QT results by following the comprehensive procedures laid-out by the FDA to promote safety and efficacy from new liquid embolic devices. The outcomes of the proposed investigations in this STTR Phase II application, combined with our previously published research results, will help jump-start the pre- clinical assessment of PPODA-QT for endovascular embolization of aneurysms.